The present invention relates to a mixer and a multiple reactive component dispensing device assembly, in particular a two-component cartridge, the mixer comprising a mixer housing, a mixer element group, a mixer inlet section having separate inlets for each outlet of the cartridge, the cartridge comprising at least two containers and an outlet area with separate outlets for each container, the mixer and the cartridge being provided with cooperating attaching means.
There exists a great number of mixers and cartridges having means for connecting and attaching the mixer to the cartridge, e.g. according to U.S. Pat. No. 4,767,026 or U.S. Pat. No. 4,538,920 where the mixer has two bayonet locking lugs insertable into corresponding prongs on the cartridge. The rotary locking movement will cause contamination of one component against the other component at the interface between the cartridge and the mixer in that these components will be transported from one outlet to the other outlet, or from one inlet to the other inlet, causing an undesired reaction between them at the interface between cartridge and mixer and eventually carrying such a reaction back into the cartridge outlets, thus causing plugging of the outlets.
U.S. Pat. No. 5,228,599 discloses a multiple component dispensing cartridge having a mixer attached thereto with the aid of a coupling nut having an internal thread, wherein each storage cylinder ends in a dispensing opening which forms a common outlet, whereas the inlet of the mixer is not defined. The mixer is put on the cartridge and secured with the coupling nut screwed on an external thread at the cartridge.
DE-U-94 05 922 discloses a two component cartridge wherein the containers are arranged concentrically and whereas the outlets are side by side and D-shaped. For better discharge of the residual material two sleeves are connected to the mixer. These sleeves, however, do not prevent cross-contamination of the two components while connecting or disconnecting the mixer to and from the cartridge.
There is also a tendency towards components with faster reactivity for quicker end use, which causes greater problems with materials of construction of the package, chemical migration through the separating wall from part of the package to another and hence unwanted reaction within the package.
Cartridges separated by one single wall, e.g. according to U.S. Pat. No. 5,333,760, cannot exclude chemical migration through such a single wall separation barrier and therefore separation at the cartridge outlets is not sufficient if a reaction takes place during storage within the cylinders.